Why is Giardia a bad protist?

Giardia is considered a harmful protist because it causes giardiasis, an intestinal infection that leads to symptoms such as diarrhea, abdominal pain, and nausea. It is transmitted through contaminated water, making it a significant public health concern, especially in areas with poor sanitation. The parasite can disrupt nutrient absorption in the intestines, leading to weight loss and malnutrition. Additionally, Giardia can be challenging to eliminate from water supplies, posing ongoing risks to affected populations.